Method and system for indicating or controlling train spacing



Feb, l0. 1925. Y

. F. w. GARDINER METHOD AND SYSTEM FOR INDICATING OR GONTROLLING TRAIN SPACING Filed May 19, 19 22 Freins/wwf MGF/mauve@ Feb, 10. 1925.

n 1,526,130 F. W. GARDINER METHOD AND SYSTEM FOR INDICATINGr OR CONTRYOLLIANG TRAIN' SPGING ,mvENToR Haenen/0K W @Hanf/vs@ Patentedl Feb. 1o, 1925.

FREDERICK W. GARDINER, OF YONKERSNEW YORK.

METHOD AND SYSTEM'FOR INDICATING O EtA GONTROLLING TRAIN SPACING.

Application led May 19, 1922. Serial No. 562,267.

To all whom t may concern:

Be it known that I, 'FREDERICK W. GARDI- NER, a citizen of the United States of America, residing at Yonkers, in the county of Westchester and State of New York, have invented certain new and useful Improvements in Methods and S stems for Indicating or Controlling Train pacing, of whichv the following isa specilication.

My invention relates to a method and system for indicating or controlling the spacing of trains, and my object is to provide a safety system against collision, but also permits the operation of an increased number of tra-ins with safety on a given length of track. Either signal or train control devices, or both, may

- be utilized as desired.

The invention contemplates as its underl lying thought, a signal or train-control device carried by the oncoming train, and the operationof which is governed by the appreach of the oncoming train toward the train ahead, through means actuated in partV by the oncoming train, and in art from the train ahead.- Various em iments of this idea will occur to students of the roblem, and for simplicity I have conline my vexposition of the thought to a single embodiment more or less diagrammatically shown in the accompanying drawings, in Which- Fig. 1 is a diagrammatic plan of a system which illustratively Fig. 2 is abroken vertical section through a combined indicator and control device carried by the oncomingl train; and F Fig. 3 is a broken section on the line 3 3,

i 2. r.glhe usual block signal Systems commonly 'employed on railways seriously limit the track capacity-that is to say, the number of trains which may be operated'with safety within given block limits. They have, moreover, Lcertain objectionable features. .They are dependent, for exaiiple, upon visibility from the engineers cab, and at night upon the integrity of the signal lamps. In heavy fog, both are difficult to see, while the breakage of signal lamps is a common occurrence. In'any event, constant watchfulness on the part of the engineer is essential, since the signal is located at a definite point along the trackway, and unless observed as approached, a'ords no indicawhich not only guards' embodies the invention tion of the approach of the oncoming train to the train ahead.

The signal or an automatic train-control device, or both. It is self-contained by the trains affected, save so far as the track rails or cuit. Preferably the operation of the signal or train-control mechanism is variedk with the speed of approach of the oncoming train. l

In the illustrative lay-out of Fig. 1, the rear car of the train ahead is indicated at 10, while the forward car of the oncoming train is indicated at 11, both trains being headed in the same direction on the track rails 12, 13. It will be noted thatthe axles 14 and 15 of the two trains form, with the track rails 12 and 13, of varying length between the trains. In this loop I induce a secondary current from a source of current suchas a highfrequency generator 16 carried by the train ahead, and having associated therewith a primary coil 17 suitably disposed with respect to the track loop to induce current therein.V l

At the front of the car 11 of the oncoming train is a pick-up coil 18, which is Suitably disposed withA respect to the track rails 12 and 13 to derive current from the induced current in the track loop. Through the medium of a detector-amplifier 19, this present system may operate either a their equivalent enter into the actuating cira closed circuit loo-pv derived current is stepped up to sufficient potential to operatea solenoid 2O which in turn operates the escapement 21 ofa ratchet 22. In the circuit of the sending loop 17 I` arrange an interrupter 23 operated by any suitable connection from the running gear of the car 10 of the train ahead;,for example, by means 'of aV cam 24 connected through suitable gearing 25 with one of the car axles. It is thus obvious that when the circuit of the primary sending coil 17 is closed by the interrupter'24c and current is induced in the track loop, it will be picked up by the coil 18 of the following train and will be amplified sufficiently to operate the solenoid 20 and thus the escapement 21.

loo

The ratchet 22 controlled by the escapethe gear train 30,l 31, and'32 drives a spindle 33 carryingnthe gear" 34 of ,a differential. Associated with the`latter is aff-cooperat1ng gear 35 in the form of aninternally toothed ring carried by a sleeve36, which surrounds planet pinion 47 carried by an arm 48 fast with the sleeve 49, to which is slidably keyed an indicator disk i. The latter has a peripheral thread 5l which engages the interna-l threads 52 of a stationary casing 53, in which the indicator disk 50 rises or falls, through its threaded engagement, depending on the direction of rotation of @the sleeve 49. On the lower face of the indicator disk 50 is acontact 54 adapted to engage a 'cooperating contact mounted on a carrier 56. When the contacts 54 and 55 are in engagement they close a circuit'57 adapted to operate a train-control device (not shown), such as a brakesystem.

Thile the contact carrier 56 may be stationary, I prefer to sub-ject it to the influence of a speedometer 58, for the purpose of advancing the engagement between the co-u operating cont-acts 54 and 55,/when the oncoming train approaches a-t high speed. The advance of the engagement between the contacts may ,be increased by arranging between the speedometer 58 and lthe contact carrier 56 a pair of eccentric gears 59 and 60, the former fast with the speedometer, while the gear is fast with the hub 61 which carries the contact carrier 56.

The operation of this specific embodiment of my invention will be readily understood. Assuming both trains -to be advancing at the same speed, and in the same direction, the rotation of the gears 34 and 35 of the differential in opposite directions, is at the same peripheral vspeed and the position of the planet pinion 47 will remain stationary.

The indicator disk 50 therefore will not be rotated. It may be stated that the train,

of gears 37-46 is so predetermined that the speed of drive ofthe gear 35 is s o harmonized with` the drive-of the gear 34 by the spring 27, (under the-control of the. 'escapement 21 operated rthrough the track loop from the interrupter 23 of the train ahead) that when the trains are moving at the same speed, the gears are rotated at the same. peripheral speed'. Y

Assuming that vthe train ahead, 10, slows` down or stops, while the oncoming train l1 continues to approach, the gear 34 of the dilerential is now halted, or rotates at slowf er speed by reason of. the slower operation, or the cessation, of the interrupter 23 which controls the escapement 21. Since the gear 35 continues to be rotated by the oncoming train, the'planet pinion 47 is rolled around the gear 34, and through the arm` 48 rctates the sleeve 49. and the indicator disk 50, thus causing the contact 54 to approach the contact 55 and eventually bringing them into engagement when a dangerous spacing of the tra-ins has been reached.

If ythe oncoming train should pick up speed as it approaches the train ahead, 10, its speedometer 58 will rotate the gears 59 and 60 and will thus advance the contact 55 toward the approaching contact 54, so that the operation of the automatic trainr stop mechanism will occur at a spacing between the trains which is suiiicient to insure the halt of the oncoming train at a safe distance from the train ahead.

If the oncoming train ll-should halt while the train ahead proceeds, the gear 35 is stationary, while the gear 34 is rotated with the result that the planet pinion 47 now runs around in the opposite direction and consequently shifts the contact 54 away from the contact 55. At the same time theindicator disc 50 rises'in its casing 53 through its engagement with the threads of the latter, and the indicator 50 mayL make complete revolutions in'this direction without bringing the contacts 54 and 55 into engagement.

The indicator50 may be of any `suitable type. I haveshown it in the form of a screw ring or diskv having a peripheral face bearing legends 62, which are visible through ythe sight hole 63 in the casing 53. It is of course immaterial whether or not the engineer of the oncoming train shall observe the spacing between the trains when they are far apart, and it is only when the trains approach each other that the legends on disk 50 become visible through thesight hole 63 in' the casing 53.

0f course both the indicator and the'A The function of the connection is merely to control the rotation of the gear 34 of thel differential carried by the oncoming train, and any. suitable arrangement for this purpose may be utilized to carry out my purposes.

In order to properly set the indicator or control device of an outgoing train with re spect to a train preceding it on the line, various expedients are obviously available. For example, at apredetermined distance or distances from the terminal from which the trains start, signal stations may be placed which notify the terminal of the arrival of the train at that point. The indicator of the outgoing or following train will then be set to a corresponding position and the train dispatched.

the position of the train ahead is readilyl secured by providing at the dispatching lif) terminal a receiving instrument of the general character ofthat installed at the head ofthe following train, said receiving instrument being connected to a receiving coil located in fixed position between the track rails and preferably slightly in advance of the dispatching point of the outgoing traan-'This instrument receives the current impulses from the preceding train on "the line and-operates the dispatching vstation indicator which thus shows the distance which that train has advanced on .the line. When the next train departs its indicator is set to. correspond with the dispatching station indicator.' Thereafter the departing train receives its impulsesdirectly from the train ahead in the manner set. forth.

-These expediente form obviousmeasures for the initial setting -of the indicators at the train dispatchingstat'ion. Other y,means will readily occurfto those dealing with the problem which do not affect the underlying principles of the invention.

. It will be obvious furthermore that when a train is not in service, its signal or control mechanism may be V,readily cut out if desired, by operating a clutch in the drijve connection from the train axle and a switch in the control circuit 57.

The system outlined is particularlyv valuable for railways in which trains are run close together, for example in suburban traffic, or in subwayor elevated systems in which increased track capacit-y combined with safety isa problem not hitherto solved. Attention `may be drawn to the fact that and operates should' there be any failure in the control of the gearlfof the differential governed by the train ahead, so that this gear is not rotated, although the train ahead advances, the following train will advance only a ylimited distance before the contacts 5ft-55 .i are brought into engagement `by the rotation ofthe gear 35 incident to the travel of the oncoming train. vSince the driveo-f the gear 35"by `the oncoming train is positive, there is little danger of. failure. Should the latter break down, however, danger would result; but 'this is unlikelyand moreover, it may be readily indicated by some 4signal device or the like which notifies the engineer that the gear 35 isnot rotatin For exam le series of contacts (not shown) may be arranged around the periphery of the gear and cont-acting with a brush (not shown)A .in a signal circuit. If the gear 35 should fail to rotate, this signal circuit would notify the engineer, or operate some safety device in a -manner readily `understood by those skilled in the 'art -ling the spacing of trains the following train,

It is tobe understood that the wo-rd train is used in lthe specificationl and claims in a Sense broad enough to include It is of course obvious that in a complete railway system, each of the trains will carry both receiving and transmitting elements, one at thc front and the other at the rear of ,the train. It will further be 4obvious that if the control of the oncoming train is not desired, the braking ycircuit connections may be omitted, andy dependence placed wholly on the indicator or signal device; or vice versa, although l prefer the double protection illustrated and described.

The gear connection high frequencycircuit closer 24 and con- 21 is operated at suitable intervals, `so as to permit the ratchet 22 .to rotate one com- `plete revolution to every 240 revolutions of the `axle of the train ahead. train of gears for operating the gear 41 of the train which drives the gear 35 of the differential from the axle 15 of the oncomingtrain is such as' to operate the gear 4l a complete revolution for every 240 revo lntions of the axle 25. Asabove stated,

Similarly the thege'ar train operating the'gears 34 and Sois such vthat they are operated at the same peripheral speed in opposite directions when the spaced trains are traveling at the in part directly by the oncoming train and in part by the train ahead through the intermittent interruption of the circuit betweenthe trains. v i

2. The method of indicating or controlwhich comprises governing a differential control carried by the following train, in part from the running gear of the latter, and in part from the running gear of the train ahead. thro-ugh the intermittent interruption of an electric circuit between the trains.

3. The method of indicating or controlling the spacing of trains which comprises governing a differential control carried by in part/from the run- 'tact maker 23 is such that the escapement ning gear ofthe latter, and in part from the running gear of the train ahead through an electric current induced in the track rails.

'4. In a system for indicating or control-- ling the spacing of trains, an operating member carried by the following train, actuating-.means therefor, and means governing 80 for operating the said actuating means, said governing means 'being-operatively responsive to the movements of the spaced Vtrains and electrically controlled` from one of said trains through a current induced-in the traclcrails.

5. In a system for indicating'or controlling the spacing of trains, ai' differential, means directly controlled by the running gear of one of said trains for driving one element of the differential, and meanscontrolled'from the other of said trains through an electric circuit forv driving the other element of theJ differential in accordance with the speed of Athe latter train, together with an operating mechanism actuated -by the differential.

6. In a system for indicating or control ling the spacing of trains, a differential,

means controlled by the running gear of the spaced trains for driving respective elements of the differential, and an operating mechanism actuated by the differential.

7. In a system for indicating or controlling the spacing of trains, a. differential carried by thefollowing train, means operatedby the running gear of the latter for driving one element of the differential, means electrically. controlled from the train ahead inl accordance with its speed for driving another element of the differential, and operating means actuated by the differential.

8. In a system for indicating or controlling the spacing of trains, a receiving dey vice at the forward end of a train for establing electrical communication with the train ahead, in combination with a means carried by the train ahead for inducing current in the track rails between the trains.

9. The method of indicating or controlling /the spacing of trains which comprises governing a differential' control carried by the following train, in par@ from the runninggear of the latter, and'inpart through a circuit interrupter operated by' therunning gear ,of the train ahead.

10. The method of indicating or control- Y ling the spacing of trains which comprises governing a dierential control carried by the following train, in part from the running gear of the latter, and in part `from the running gear of the train ahead, through a current imposed upon the rails betweenY the juxtaposed trains. v l

l1. In a system for indicating or controlling the spacing of trains, an operating member carried by the following train, actuating means therefor, and means governing said actuating means, said governing means being operated responsive to the -movements of the spaced trains, and being independent of eachother, one of said governing means being responsive to the intermittent interruption of current between the trains, such interruption being dependent upon the speed'of one of said trains.

12. In a system for indicating or controlling the spacing of trains, an operating member on the following train", and means governed by the running gears of the spaced 'trains for actuating said .member, together with operating means controlled at least in part by a current induced in the track rails between the spaced trains.

13. In a system for indicating or controlling the spacing of trains, a trackway, a series of trains headed in the same direction on said trackway, means carried by the several trains forinducing independent electric currentsI in the track rails between each train 7and the one following, and operating means governed at least in part by said currents. l

14. In a system for indicating or controlling the spacing of trains, an indicator or control device carried by the following train, means positively driven by the advance of said train for actuating said device in proportion yto the advance of said train regardless of speed, and means associated lwith the train ahead and operated regardless of its speed of advance for varying the drive of said device in accordance with the advance of said train ahead.

In testimony Whelleof'I have signed my name to this-specification. i

' FREDERICK W. GARDINER. 

